Hey guys. . .
As some of you know, I'm in the design stages of a compound turbo set up utilizing a modified stock turbo and a modified H2E. I am waiting to do any real work on it till I get my next oil sample analyzed(2000 more miles.) Depending on the results of that test is whether I will pull my motor and do a rebuild on it or not. If I do that, I am planning on upgrading the rods and adding a main gurdle. I have forged rods, but how much can they take? This setup is going to put me well in the the 70+ PSI range, I am expecting quite impressive performance numbers. Hmax says hes got a wheel for the H2 that could put me in the 80 or 90 PSI range. But we're going to start off small to see how the turbos work together. So where do you guys recommend getting rods, and what rods are they? How much? Same for the gurdle? Is there any other parts you think I should invest in? Ceramic coated pistons? Is it a good idea to have the crank turned if need be? or buy a new crank? Sorry for the length, thanks guys.
Tim

 

For that kind of setup, and especially if you are looking for big numbers, you need to get some foundation work done. If you're planning to push 70+ psi, you're well over the 500 hp mark, and that's not where you want to take stock forged rods.

As far as which rods to get, I'm not exactly sure which ones are the best. That's up for debate. I'd suggest talking to some of the guys who have run some of these top hp engines and see what their recommendations are.

If you are going to spend the time to put compounds on, and the work that goes with setting it up right, definately spend the little extra time and money to get the bottom half of that engine ready for that kind of power. If not, you'll be right back in the garage yanking that engine out in no time. I have not built a 500+ hp PSD, but I have built some engines in the past, and you'd be surprised what can go wrong if you don't plan ahead.

Good luck with the project, and POST PICTURES OF YOUR PROGRESS PRETTY PLEASE WITH SUGAR ON TOP!!!!!!

 

Im doing a compound turbo as well, the 1.15/ww/ATS as the small turbo and one as the large one. For this build i would suggest visting www.wipeoutenterprises.com, WOE has alot of ingenuitive things. Their main girdle ties the caps into the pan rail, that was an idea me and my teacher thought up. It can be done for much less than $2700 however.

Main studs, Main girdle, cryoed block, billet connecting rods, Arias forged teflon and ceramic coated pistons for the bottom end, and you have the top end pretty straight, but i would get roller rockers for efficiency and that higher spring load. Also some porting, i have a dummy head i am experimenting with and it looks pretty good. Aluminum intake plenums to hold more boost, of course you'll need head studs and a fire-ringed block. Im planning on doing all of the above, with some garden-hose size injectors. I want to send the parts out to WOE and have the crank lightened and the rotating assy balanced, bore the block, cryo it and send back all the new parts, and then i can assemble it. That's the plan but it takes alot of money! You may want to look into a custom ground cam as well.

 

I just dont see the ben of twins on a 7.3... there are many trucks over 600hp on singles that are daily drivers. You almost always loose the AC unit, not knocking just I think there are better ways to do the same thing...

 

Tim, I give you props for taking on such a project. I would definately look into building up the bottom end. You might give Black Widow Diesel, Diesel Innovations, or Wide Open Performance a call to get some opinions on the hard parts for the bottom end.


Kris, you sure you want to go with the Arias pistons?

 

Kris i think its great you are always thinking about ways to make things better. You really need to get on another forum thats a little more performance oriented and you will see many of the things you listed arent needed and some dont work period. Arias pistons are junk and will wear out if very quick in a street truck, cant remember the exact reason but no one is running them. Mahles are the way to go. I agree WOE has some neat stuff, im running thier connecting rods, main studs and push rods. If you buy thier con rods you will not be able to lighten your crank... I had to have heavy metal added just to balance the rotating assembly. I cant remember how much heavier they were than stock but it was a fair amount. IMO cryo is over rated, so are girdles, teflon/ ceramic coatings and fire rings. I had to build mine on a budget and i felt those were places i could save some $. So far so good and i beat the snot out of it daily with LOTS of passes down the track, many of them with nitrous.



Exactly. I dont know of a whole lot over 600 with singles and fuel only, but definatly quite a few at or over 550 on a single.

I dont mean to sound like an a hole, but why in the heck would you want to use a modded h2 as your big turbo? It works great by itself, with lots less plumbing and will support 550 hp on fuel.

 

Yes, see i need to learn a few things as well. Sounds like i won't do the Arias' then. I would like to hang around a more performance oriented site, but TDS is just too annoying and childish for me and i go there for 5-10 minutes at a time and then i'm fed up with people 2-3 times my age acting like little kids. So are you saying the WOE rods are super-light, which means you don't need to remove any from the crank? I would like to keep the crank as strong as possible and that would be a way. My teacher is a 358 sprint car crew cheif, and the owner of the car has a huge machine shop, where the car is kept. We are doing a custom WOE-style girdle for much less money, and custom stacked stock HPOPs. Lots more custom things that are at this point, because we haven't experiments. Im picking up the engine tonight and then we can play from there.

 

Pretty sure the WOE rods are much heavier, not lighter.

 

Hey all. Thanks for the input. I figured now would be a good time to beef up my bottom end. Anyway, the reasons for the compounds is this. Yes the H2E is a fantastic turbo with lot of power potential. But its power is good on the pulling track. . . no good for drag racing. The turbo lag is very very evident. . . remember I have a stick. A modified H2E would have even more lag when we're talking about 70-90 PSI. With a compound setup. . . I can have best of both worlds. . . just will take a lot of time, work and money. Right now I'm thinking main studs, girdle, crowey(SP?) rods, Mahle ceramic coated pistons. I really don't think the strength of the block is an issue unless somebody else has experience to tell otherwise. I already have the upperend done. I don't plan on doing any grinding on the heads. . . I have to make new intake manifolds to relocated them somewhere around the stock fuel filter. Anyway, thats where I'm at. Keep the thoughts coming. This is a group effort!
Tim

 

that is correct.